Fuel injection pump mechanism



March 20, 1951 L. E. JOHNSON 2,545,564

FUEL INJECTION PUMP MECHANISM Filed April 21, 1947 2 Sheets-Sheet l INVEN TOR.

A/0,15 54m W ATTORNEY March 20, 1951 E. JOHNSON 2,545,664

FUEL INJECTION PUMP MECHANISM Filed April 21, 1947 2 Sheets-Sheet 2INVENTOR.

1/ /44 Lam BY ATTURNEY its rotation with relation thereto. 45,is cutaway or notched as indicated at 49 and the control gear 34, as shown inFig. 2, is relieved as at 50.

3. in Fig. 2, and meshes with a control gear 34 fixed to and rotatablewith a shaft 35. The shaft 35 is connected through mechanism, notillustrated, with similar shafts for other pumps of multicylinderengines and with the engine governor control for rotatable adjustmentrelated to the fuel requirements of the engine as is common practice.Thus, as the governor responds to the demands of the engine for more orless fuel, the shaft 35 is rotated. Through the meshing gears 32 and 34the plunger is rotatably adjusted to efiect metering of the requiredamount of fuel through its scroll shape relief Hi. It is apparent,therefore, that in placing the pump assembly into the pump housing, itis essential that the gears 32 and 34 come into meshing engagement intheir proper phase positions in order to maintain the requiredrelationship between plunger positions of the several pumps and thegovernor setting.

This is accomplished by a construction of the pump assembly designed toprevent its removal from or insertion into the pumphousing except whenboth of the gears 32 and 34 are in a certain position. For convenience,this position has been taken as the shut-off or no fuel position of thegovernor and the plunger. of the drawings, this position is establishedon the gear 34 by a shoulder 38 engageable with a stop As shown in Fig.2

screw 39 arranged to project through the housing enclosing the gear.

The plunger gear 32 is retained against rotation away from its no fuelposition by the following mechanism. Referring to Figs. 1 and 3 the cupshaped member 26 surrounding the "plunger gear 32 is shown as heldagainst rotation with relation to the sleeve 22 within which it in theedge of the washer 25 so that in assembly [the top surface of the key isengaged and the key retained against vertical displacement by v-pressure.of the spring 23 where it seats on the Qiwasher 25.

A dished washer 45 (Figs. 1, 4 and 5) is retained in, and serves as anend member for the sleeve 22 by means of a snap ring 46. This washer hasears 41 projecting radially and engageable with notches 48 in the bottomof the sleeve to prevent The washer It is, therefore, only when thenotched portion 45 of the washer properly registers with the controlgear in its no fuel position that the fuel pump assembly can bewithdrawn from the bore II in the pump housing.

"To prevent rotation of the pump plunger and the plunger gear 32 afterthe assembly has been withdrawn and, therefore, to insure that the vgears 32 and 34 will be in their proper phase positions uponre-insertion of the pump assembly,

the gear 32 is held against rotation by the following means. An upwardlyprojecting ear 52 is bent from the washer 45 and adapted to registerwith a perforation 53 (see Fig. 5) in the bottom gear 32 is in its nofuel position, the spring 23 urges the plunger, together with its gearand cup 26, downwardly because upon withdrawal the lower end of theplunger I5 is no longer restrained by the cam 30. The downward movementof the cup 26 under influence of the spring 23 is limited at theposition illustrated in Fig. 5 wherein'the cup engages the washer45, andin this position the ear 52 extends through the perforations 53 and intothe slot 54 to prevent rotation of the gear 32 and thus to retain thegear in its proper phase position for re-assembly.

When the construction described the washer member prevents removal ofthe pump assembly from its housing except when the meshing gears "areboth in a pre-determined phase position. Furthermore, it preventsre-assembly unless'the gears are in this position and it serves, throughits upwardly bent ear 52, to prevent rotation of the pump plunger awayfrom this pre-determined position while the parts are disassembled. I

The control gear 34 herein illustrated is representative of any controlmember adapted to register or mesh with the plunger gear 32 and may bevaried in its construction without forfeiting the advantages of thepresent invention. For example, in some installations a straightrack-bar is employed for registry with the plunger gears of a pluralityof aligned fuel injection pumps and the invention herein described willapply in such construction so long as means are provided forestablishing a definite no fuel position of the rack-bar.

' I claim:

1. In a fuel injection pump for an internal combustion engine, a pumphousing, a pump assembly removably disposed in the housing, means foradjusting the pump including parts carried by the housing and partscarried by the pump assembly and registering with each other, and meansto prevent removal or replacement of the pump assembly except when theregistering parts are in a predetermined phase position, and meansoperable upon removal of the pump assembly to retain said parts carriedby the pum 2. In a fuel injection pump for an internal combustionengine, a pump housing, a pump assembly removably disposed in thehousing and including a plunger adjustable by rotation for metering fueldelivered by the pump, a gear like part on the plunger, a gear like partin the housing meshing therewith and adapted to be controlled by anengine governor, and means to prevent removal of the pump assembly fromthe housing except when said meshing gear parts are in a predeterminedphase position, and means effective upon removal of the pump assembly tolock the plunger against rotation in the pump assembly.

3. In a fuel injection pump for an internal combustion engine, a pumphousing, a pump assembly removably disposed in the housing and includinga plunger adjustable by rotation for metering fuel delivered by thepump, a gear on the plunger, a control gear in the housing meshingtherewith and associated with an engine governor, means to stop thecontrol gear in a predetermined phase position, said control gear havinga relieved portion in its periphery, and means on the pump assemblypreventing its removal except through said relief when the control gearis'in said position.

4. In a fuel injection pump for aninternal means on the pump assemblypreventing its removal except through said relief when the control gearis in said position, and means for looking the plunger gear againstrotation in the pump assembly in a corresponding phase position when thepump assembly is removed from the housing.

5. In a fuel injection pump for an internal combustion engine, a pumphousing, a pump assembly removably disposed in the housing and includinga plunger adjustable by rotation for metering fuel delivered by thepump, a gear on the plunger, a control gear in the housing meshingtherewith and associated with an engine governor, means to stop thecontrol gear in a predetermined phase position, said control gear havinga relieved portion in its periphery, and means on the pump assemblypreventing its removal except through said relief when the control gearis in said position, and means for locking the plunger gear againstrotation in the pump assembly in a corresponding phase position when thepump assembly is removed from the housing, and releasing the plungergear when the pump assembly is replaced in the housing.

6. In a fuel injection pump assembly adapted to be contained by a pumphousing and having a plunger of the metering type with a gear forimparting metering adjustment thereto, a sleeve surrounding the plungerand having an end member through which the plunger extends forengagement with an actuating cam, spring means in the sleeve urging theplunger into contact with said cam and tending when the assembly isremoved from the housing to position the gear on the plunger adjacentthe end member of the sleeve. and means carried by said end member andengageable with the gear to prevent its rotation in the pump assemblywhile the pump assembly is removed from the housing.

7. In a fuel injection pump for an internal combustion engine, a pumphousing, a pump assembly removably disposed in the housing and includinga plunger adjustable by rotation for metering fuel delivered by thepump, a gear like part on the plunger, a gear like part in the housingmeshing therewith and adapted to be controlled by an engine governor,means to prevent removal of the pump assembly from the housing exceptWhen said meshing gear parts are in a predetermined phase position, aspring for retracting the plunger, and means actuated by said springupon removal of the pump assembly to hold said first named gear likepart against rotation in the assembly.

LLOYD E. JOHNSON.

REFERENCES orrEn The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS Number Name Date 1,974,858 Baur et al Sept. 25,1934 2,185,144 Edwards Dec. 26, 1939 2,187,732 De Juhasz Jan. 23, 19402,372,694 Tabb Apr. 3, 1945

